OVERFLOW under-sump NO DRILLING OF AQUARIUM while the fish is inside + Automatic Water Change Pt.1

I have been wanting to convert my 90 gallon tank from an overhead-sump into an under-sump so I could increase the water volume of my aquarium in order to avoid sudden swings in water parameters. The glass thickness of my tank is 1/4" thick, I might just break the glass if I drill a hole through it so I thought of using an overflow system via gravity. I added an automatic water change system because it takes me an hour to remove and refill the water, well thank you to wifi powerstrips I was able to schedule water changes via my phone. Part 2 is on the way.
Materials used:
1-1/2" diameter
1pc pipe
2pcs cap
2pcs 1-1/2 x 3/4 coupling reducer
1pc tee
1pc elbow
3/4" diameter
2pcs pipe
8pcs elbow
1pc elbow threaded
2pcs Female threaded coupling
1pc ball valve
1pc tee
1pc union
1pc hose snap on male adapter
1pc hose snap on coupling
Sobo WP-7000 5500 lph